The field of the invention relates to the explosive shaping of metal tubing.
The shaping of metal tubing has commonly been accomplished by means of a spinning apparatus. The tubing is rotated about its longitudinal axis at high rpm while a spinning roller tool contacts its outer surface. If aluminum tubing is to be shaped by this process, relatively costly material is required as there must be "0" temper in aluminum. The process is essentially limited to circular deformations.
Explosive shaping of metal structures including tubing has been known for some time. U.S. Pat. No. 3,136,049 discloses a method wherein a cylinder blank is placed into a split die having a desired configuration. A string explosive charge is centered within the blank which is then filled with a fluid such as water. Upon detonation of the explosive, the shock waves are transmitted by the fluid forcing the cylinder blank to conform to the configuration of the die. FIGS. 3 and 4 of the patent are illustrative of the process.
U.S. Pat. Nos. 3,206,845, 3,235,955, and 3,252,312 are representative of the art of explosive shaping as it stands today.